title: Effective inhibition of bacterial respiration and growth by CuO microspheres composed of thin nanosheets.
abstract: This study describes the synthesis, characterization and biocidal potential of copper oxide micro-spheres composed of thin sheets (CuOMSs-Ths). Microscopic observations of synthesized CuOMSs-Ths revealed the clusters of thin sheets arranged in small flower like micro-spheres. Diameter of each micro-sphere was determined in the range of 2-3 μm, whereas the size of each sheet was ∼ 80 nm. These micro-flowers like nanostructures were synthesized using copper nitrate hexahydrate and sodium hydroxide via solution process. The CuOMSs-Ths exhibited a broad-spectrum anti-bacterial activity involving significant growth inhibition of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Micrococcus luteus. The IC50 values of these engineered NPs against E. coli, P. aeruginosa, S. aureus and M. luteus were determined to be 195, 200, 131 and 184 μg/ml, respectively. Also, the respiration of Gram+ ve organisms (M. luteus and S. aureus) was inhibited significantly (p value < 0.005) at relatively lower concentrations of 12.5 and 50 μg/ml, respectively, as compared to the Gram- ve bacteria (E. coli and P. aeruginosa), where the growth inhibition occurred at a much greater concentration of 100 μg/ml. The results explicitly demonstrated anti-microbial activity of CuOMSs-Ths with a higher level of toxicity against the Gram+ ve vis-a-vis Gram- ve bacteria.
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Rizwan
authors.initials: R
authors.lastname: Wahab
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Shams Tabrez
authors.initials: ST
authors.lastname: Khan
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Sourabh
authors.initials: S
authors.lastname: Dwivedi
authors.affiliation: King Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Maqusood
authors.initials: M
authors.lastname: Ahamed
authors.affiliation: Department of Agricultural Microbiology, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh 202002, India. Electronic address: musarratj1@yahoo.com.
authors.forename: Javed
authors.initials: J
authors.lastname: Musarrat
authors.affiliation: Department of Zoology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Abdulaziz A
authors.initials: AA
authors.lastname: Al-Khedhairy
mesh_terms: D000332:Aerobiosis / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D003300:Copper / Q000494:pharmacology*; D003460:Crystallization; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D057446:Hydrodynamics; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects / Q000254:growth & development; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D055672:Static Electricity
chemical_list: D003300:Copper; C000520:cuprous oxide
keywords: Antibacterial activity; CuOMSs-Ths; Microspheres; Nanoparticles, E. coli; X-ray diffraction pattern